Marc A. Thiessen (born 1967) is an American author, columnist and political commentator, who served as a speechwriter for United States President George W. Bush (2004–2009) and Secretary of Defense Donald Rumsfeld (2001–2004).
Thiessen's articles have appeared in the Los Angeles Times, National Review, The Wall Street Journal, The Washington Post, The Weekly Standard, USA Today and other publications. He has also appeared on Fox News, CNN, NPR, and other media outlets. In its January 11, 2010 issue, The Daily Telegraph named Thiessen number 97 of the "100 Most Influential Conservatives in America".
Thiessen grew up in Upper East Side in Manhattan, where both his parents were doctors and "left-of-center liberal Democrat types." His mother grew up in Poland and fought as a teenager in the Warsaw Uprising, a military struggle in which his grandfather died.
He wrote the 2010 New York Times bestselling book, Courting Disaster, in which he argued that the enhanced interrogation techniques used by the CIA, which the Obama administration has characterized as torture, are not torture by any reasonable legal or moral standard and "were not only effective, but lawful and morally just".
Thiessen has worked in Washington for many years, starting with five years at Black, Manafort, Stone and Kelly. He spent six years (1995–2001) on Capitol Hill as spokesman and senior policy advisor to Senate Foreign Relations Committee Chairman Jesse Helms (R-NC). He joined the Bush administration as Chief Speechwriter for Donald Rumsfeld in 2001, then moved to Bush's speechwriting team in 2004. In February 2008, he became chief speechwriter when William McGurn resigned. 
Thiessen's first book, Courting Disaster: How the CIA Kept America Safe and How Barack Obama Is Inviting the Next Attack (ISBN 1596986034), was published by Regnery Publishing in January 2010. The book is endorsed by the former Vice President Dick Cheney, former Secretary of Defense Donald Rumsfeld, and former Attorney General Michael Mukasey. It reached the No. 9 spot on the New York Times Best Sellers list for hardcover nonfiction in February 2010.
Jane Mayer, author of The Dark Side: The Inside Story of How The War on Terror Turned into a War on American Ideals, a book which Thiessen says has fundamental errors of fact, heavily criticized Courting Disaster in a book review, claiming it is "based on a series of slipshod premises." In a long response, Thiessen defended the accuracy of his book and said Mayer's review contained many factual errors and omissions. For example, Mayer quoted the head of Scotland Yard's anti-terrorism branch in 2006 as saying that Thiessen's account of the Heathrow plot is "completely and utterly wrong"; in reply Thiessen quoted a former senior CIA official as saying that the CIA liaises only with MI6 and MI5, so the Scotland Yard official "would have no way of knowing what intelligence the CIA shared with MI6 or MI5, much less the ultimate source of that intelligence". Thiessen added, "The week her article appeared in The New Yorker, former CIA director Mike Hayden handed it out in his class at George Mason University's School of Public Policy as an example of all that is wrong with intelligence journalism today." (Hayden had earlier written a positive review of Thiessen's book for The Daily Caller.)
Thiessen's promotional tour for Courting Disaster included confrontational interviews with CNN's Christiane Amanpour and MSNBC's Lawrence O'Donnell, and an interview with Jon Stewart on The Daily Show, an uncut version of which was posted online.
- "Heard But Not Seen" by Tom Frank, Taft School Bulletin, Summer 2005, pp22-25
- MSNBC Report of Obama speech describing techniques used at Guantanamo as torture MSNBC 1/9/2009; Stout, David, Holder Tells Senators Waterboarding is Torture New York Times January 15, 2009.
- Courting Disaster, Amazon.com page.
- "Book details: Courting Disaster". Regnery.
- "Marc Thiessen Biography". MarcThiessen.com.
- "Marc A. Thiessen". Oval Office Writers, LLC.
- "President Bush Thanks Bill McGurn, Announces Marc Thiessen as New Assistant to the President for Speechwriting". Press Release. George W. Bush White House. December 14, 2007.
- Alexovich, Ariel; Klingebiel, Jacqueline (March 25, 2009). "Suite Talk March 25, 2009: Speechwriters Open New Outlet". The Politico.
- Courting Disaster: One of the most important books of the year, by Michelle Malkin, January 18, 2010
- Ralph Peters, Michael Mukasey, Andy McCarthy, January 19, 2010.
- Marc Thiessen, Mukasey Calls Courting Disaster 'Absolutely Superb', National Review, January 20, 2010.
- Web page titled "Best Sellers / Hardcover Nonfiction", February 5, 2010, New York Times website, retrieved April 20, 2010
- Courting Disaster, chapter 2
- Mayer, Jane (March 29, 2010). "A curious history of the C.I.A.". The New Yorker.
- Thiessen, Marc, "Jane Mayer's Disaster", National Review Online, April 14, 2010, retrieved April 20, 2010
- Hayden, Michael (February 15, 2010). "Former CIA Director Hayden: Thiessen's 'Courting Disaster' a must-read". Book Review. The Daily Caller. Retrieved April 20, 2010.
- Alexander, Matthew (February 27, 2010). "Courting Fear". Slate.
- Thiessen's personal website (also his website for Courting Disaster)
- Thiessen's blog
- Thiessen's op-eds for The Washington Post
- Thiessen's blog posts at The Washington Post's website